Knitting machine



Aug. 3o, 193s. Y G. BALL 2,128,688

KNITTING MACHINEy Filed oct. 11, 195'/ 17 l n wf/W01;7

- .Armen/Eng t Patented Aug. 30, 1938 KNITTING MACHINE George Ball, Nuthall, England, assignor to Aristoc Limited, Nottinghamshire, England Application October 11, 1937, Serial No. .168,462 Inv Great Britain October 12, 1936 9 Claims.

Thisinvention is for improvements in or relating to knitting machines, and is particularly but not exclusively concerned with straight bar knitting machines. As is well known, in straight bar knitting machines the jack sinkers, by which the thread is progressively'sunk into loops between the needles, are pushed forward in succession by a slur-cock operating on the jacks, a verge being provided on the sinker plate or falll0'ing bar for limiting the forward movement of the sinkers. rPractical considerations demand that there should be some slight working clearance or play between the slur-cock, jacks, sinkers and verge. This play is usually slightly greater than the thickness of a jack sinker; thus in the case of sinkers .006 thick the play will be about .008. If the slur-cock is traversed without thread being fed, the sinkers are thrown forward against the verge to their utmost extent.

When the sinkers engage a thread, however, the

tension of that thread tends to prevent their being thrown forward quite so far, the variation in sinker movement being within the limits permitted by the aforesaid play. The amount to which the sinkers are thrown forward depends upon the tension of the thread; the harsher the tension the greater is the tendency for the sinkers not to travel right up to the verge. Such variation in travel of the sinkers in turn leads to a variation in the size of the loops and so it occurs that tension Variations induce variations in loop size. Such tension variations are apt to occur in plating and splicing; they also occur when hose blanks are being produced on the three-carrier method, in which each of three courses is produced from a different thread, for When three different threads drawn from three different bobbins are employed it is impossible to ensure that the tension conditions are absolutely identical. This variation in stitch length leads to what is known as a wash board effect, and it is an object of the present invention to provide means whereby the ill effects of tension variation may be obviated or minimized.

As hereinafter appears, the aforementioned defects are cured according to this invention by the provision in a straight bar machine of a slurcock having a resiliently loaded member which operates upon the loop-forming elements (sinkers) only at the forward extremity of their travel to press each said element against the abutment (verge). As will be understood, because each element is pressed resiliently against the abutment there is no play or clearance between the working parts which may be wholly or in part taken up by the thread according to thev tension there-- of. This therefore makes for uniformity in loop size.

The invention is chiefly applicable to loopforming or measuring sinkers and when applied 5 to a straight bar knitting machine (in which the aforesaid abutment is identified with the verge) it is preferred to mount the slur-cock, or at leasty a jack-engaging part of it, resiliently.

VOne such construction will now be described in l0 detail, by way of example, with reference to the accompanying drawing, in which Figure 1 is a vertical section showing the relevant parts in a Cottons patent or straight-bar knitting machine according to this invention, and 15 Figure 2 is a plan, partly in section, of said parts.

According toy this invention the slur-cock I0, which as usual has right and left hand inclined faces I lla, I 0b, for operating upon the jacksl IIl 20 according to whether the slur-cock is traversed towards the right or towards the left, is provided with at least one spring-loaded member, Which serves to complete the movement of the jacks and to press the sinkers against the verge. 25 The spring-loaded member or members may take any convenient form, such for example as a small plate or plates, but it has been found advantageous to employ hard steel balls. Therefore at the forward extremity of each of the said 30 jack-engaging faces Illa, IIlb, there is a socket I2 in the slur-cock that houses a steel ball I3 and a spring I5. 'Ihis spring presses the ball outwards until normally the periphery of the latter projects slightly beyond the operative face 35 of the slur-cock, the end of the socket being sufciently restricted in diameter to prevent the ball from being forced out. Hence, as the slurcook is traversed in the appropriate direction, the jacks Il towards the termination of their for- 40 ward movement are engaged by this ball which therefore causes the sinkers I6 to be pressed resiliently against the Verge il, the ball yielding suiliciently to obviate undue wear on the jacks. As will be understood, when the slur-cock is 45 traversed in the reverse direction the other face of the jack, and the ball associated therewith comes into operation.

The advantage of this arrangement is that, irrespective of the tension or stiffness of the 50 thread, each jack sinker I6 is pressed right up to the verge ll, so that all the jack sinkers project between the needles to the same extent and sink loops of the same size. The extent to which the balls project is considerably exaggerated in 55 the drawing. In actual practice they will be allowed to project only a few thousandths of an inchz-preferably slightly more than the thickness of a jack sinker. Thus in the case of a machine equipped with jack sinkers .006" thick, the balls would be arranged to project .008 or .009.

The sockets or holes l2 may converge from their open ends, instead of being parallel as shown.

I claim:

1. A straight bar knitting machine such as a Cottons Patent machine embodying a row Aor series of loop-forming sinkers, a slur-cock adapted to be traversed relatively to said sinkers so as to impart thereto a loop-forming movement, and an abutment functioning to limit said movement, and said slur cock having a spring-pressed member at the front corner or termination of an inclined or bevelled portion functioning to impart resilient pressure to the sinkers at the end of their loop-forming movement.

2. A knitting machine according to claim l, wherein the slur-cock has a spring-pressed member at each front corner thereof.

3. A knitting machine according to claim 1, wherein the slur-cock has two oppositely inclined or bevelled portions and a spring-pressed member constitutes the front termination of each of said inclines.

4. A knitting machine according to claim 1, wherein the spring-pressed member is constituted by a ball.

5. A straight bar knitting machine embodying a series or row of loop-forming sinkers, means for slidably accommodating and guiding said sinkers, a fixed abutment or verge functioning to determine the limit of the forward movement of said sinkers, a slur cock, means for traversing said slur cock relatively to and at the rear of said sinkers, a series of displaceable jacks co-acting with said sinkers at the rear thereof, and said slur cock having at least one spring pressed member adapted to co-act with said jacks in succession and through the intermediary of said jacks exert resilient pressure on the sinkers at the completion of their forward movement.

6. A knitting machine according to claim 5, wherein the slur-cock has two spring-pressed balls spaced apart at its front face, one functioning during the travel of the slur-cock in one direction and the other during .the travel in the opposite direction.

7. A slur cock for use on a straight bar knitting machine, having right and left hand inclined or bevelled faces for imparting a loopforming motion to sinkers, balls housed in said slur cock one at the front corner or termination of each incline an-d a spring co-operating with each ball and normally projecting same a limited distance beyond the front face of the slur cock.

8. In a knitting machine having movable loopforming or measuring elements the extent of travel of which elements determines the loop size, and an abutment for limiting the loop-forming or measuring travel of said elements, the combination of a cam for advancing said elements towards said abutment; and a resiliently loaded member associated with the forward extremity of said cam for resiliently urging said elements up to the abutment at the extremity of their travel.

9. A slur-cock, for a Cottons Patent or other straight bar knitting machine in which sinkers are moved towards a verge by a slur-cock which travels along the line of said sinkers, said slu-rcock being provided with an incline for advancing the sinkers, and having a resiliently mounted member assocated with the forward extremity of said incline for operating on the sinkers at their forward extremity of travel to urge them resiliently against the verge.

GEORGE BALL. 

